Highly oxygen permeable contact lens materials and compositions thereof

ABSTRACT

Highly oxygen permeable hard and semi-hard contact lenses are made from the copolymer of ethylenically unsaturated siloxanylalkoxy ester monomer, ethylenically unsaturated flurocarbon ester monomer and/or ethylenically unsaturated sulfone monomer; the copolymer plastic can be modified by the incorporation of hardening, stability and/or wettability agents and methods for the manufacturing thereof.

BACKGROUND OF THE INVENTION

Oxygen permeable contact lenses in the prior art are essentially madefrom siloxane monomer and methyl methacrylate. These lenses arepermeable to oxygen; hence, allowing oxygen from the air to pass throughthe lenses and reach the cornea which allows such lenses to be worn forlonger periods of time as compared to non-oxygen permeable contactlenses such as PMMA which were available previously.

Such contact lenses were disclosed in the prior art by Gaylord, U.S.Pat. Nos. 3,808,178 and 4,120,570. Later, Ellis disclosed in hispatents, U.S. Pat. Nos. 4,152,508 and 4,330,383, the partial replacementof the methyl methacrylate monomer with dimethyl itaconate. The Novickypatents, U.S. Pat. Nos. 4,216,303, 4,242,483, 4,248,989, 4,303,772 and4,365,074, disclosed contact lenses comprised of high molecular weightof polysiloxanylalkyl esters of acrylic and methacrylic acids. The Changpatent, U.S. Pat. No. 4,182,822, disclosed contact lenses comprised of acopolymer from polysiloxanylalkyl ester of acrylic and methacrylic acidessentially the same as disclosed in the Gaylord patents, supra., thatwere copolymerized with N-vinyl pyrrolidinone or N,N-dimethylmethacrylamide.

In Ichinoche, et al., Canadian Pat. No. 1,184,341, it teaches the use oforganosiloxanyl ester monomer of acrylic and methacrylic acidcopolymerized with fluorocarbon ester monomers of acrylic andmethacrylic acids and copolymerized to produce oxygen permeable contactlenses. The LeBoeuf patent, U.S. Pat. No. 4,246,389, discloses acrylicsiloxane based polymers which also contain HEMA and/or polyvinyl2-pyrrolidinone which are suitable for use in forming water-containingoxygen permeable contact lenses.

All siloxane ester monomers in the prior art employ essentially the samealkyl bridge between methacryloxy group and siloxanyl part of thestructure; wherein, neither one used ethoxy group or 2,3-dioxypropylgroups. The organosilicone monomers of the present invention can becopolymerized with perfluoroalkyl ester monomers and/or with sulfonemonomers.

SUMMARY OF THE INVENTION

The present invention relates to a novel and new generation of contactlenses comprising of copolymers made from siloxanylalkoxy ester monomersof acrylic, methacrylic and/or itaconic acids and mixtures thereof andperfluoroalkyl ester monomers of acrylic, methacrylic and/or itaconicacids and mixtures thereof which are copolymerized with ethylenicallyunsaturated sulfone alkyl monomers and/or ethylenically unsaturatedsulfone ester monomers of acrylic, methacrylic and/or itaconic acids andmixtures thereof, to produce highly oxygen permeable and improvedmaterials for contact lenses.

The first representative siloxanylalkoxy ester monomer of acrylic ormethacrylic acid of the present invention has the general structuralformula: ##STR1## wherein X and Y are C₁ to C₆, alkyl, cyclic or phenylgroups and/or groups of the following structure: ##STR2## m being aninteger from 1 to 5 and R is methyl group or hydrogen.

The second useful organosiloxanylalkoxy ester monomer of acrylic ormethacrylic acid is represented by the following structural formula:##STR3## n being an integer from 1 to 3; wherein, X and Y are C₁ to C₆,alkyl, cyclic or phenyl groups and/or groups of the following structure:##STR4## m being an integer from 1 to 5 and R is methyl group orhydrogen.

The above disclosed new organosilicone monomers can be partiallysubstituted by additional organosiloxanylalkyl ester monomers from theprior art. The first representative partial substituteorganosiloxanylalkyl ester monomer of acrylic and methacrylic acid fromthe prior art has the structural formula: ##STR5## wherein, X and Y areC₁ to C₆, alkyl, cyclic or phenyl groups and/or groups of the followingstructure: ##STR6## m being an integer from 1 to 6, n being an integerfrom 1 to 3 and R is methyl group or hydrogen.

The second useful partial substitute organosiloxanylalkyl ester monomerof acrylic and methacrylic acids is represented by the followingformula: ##STR7## wherein, X and Y are C₁ to C₆, alkyl, cyclic or phenylgroups or groups of the following structure: ##STR8## m being an integerfrom 1 to 6, n being an integer from 1 to 3, A is selected from C₁ toC₆, alkyl or phenyl groups, R is methyl group or hydrogen and D ishydrogen or hydroxy group.

The third useful partial substitute organosiloxanylalkyl ester monomerof acrylic and methacrylic acids is represented by the followingstructural formula: ##STR9## wherein, X and Y are groups of thefollowing structure: ##STR10## m being an integer from 1 to 5, n is aninteger from 1 to 3; wherein, A is selected from C₁ to C₆, alkyl, cyclicor phenyl groups and R is methyl group or hydrogen.

The fourth useful partial substitute organosiloxanylalkyl ester monomerof itaconic acid is represented by the following formula: ##STR11##wherein, X and Y are C₁ to C₆, alkyl, cyclic or phenyl groups or groupsof the following structure: ##STR12## m being an integer from 1 to 5, nbeing an integer from 1 to 3; wherein, A is selected from C₁ to C₆,alkyl, cyclic or phenyl groups and B is methyl group, hydrogen orhydroxy group.

The perfluoroalkyl ester monomers of acrylic and methacrylic acid arerepresented by the following formula: ##STR13## n being an integer from1 to 3, R is methyl group or hydrogen, m being an integer from 1 to 4, abeing an integer from 1 to 10 and Z is fluorine or hydrogen.

Another useful perfluoroalkyl ester monomer of the present invention isrepresented by the following formula: ##STR14## and telomer alcoholmethacrylates or acrylates of the following formula: ##STR15## andmixtures thereof; wherein, n is an integer from 1 to 10, m is an integerfrom 1 to 5 and R is methyl group or hydrogen. Particularly useful inthe manufacture of the lenses of the present invention are thosefluoroalkyl esters selected from the group consisting of perfluoroalkyethyl acrylates and methacrylates of the following formula: ##STR16##wherein, n is an integer from 1 to 10 and R is methyl group or hydrogen.

The perfluoroalkyl ester monomers of itaconic acid useful in the presentinvention for the manufacturing of contact lenses are represented by thefollowing formula: ##STR17## n being an integer from 1 to 4 and m is aninteger from 1 to 10.

Additional perfluorocarbon monomers useful in the present invention toform copolymers are found in the European Patent Application No. 0084406by David E. Rice, et al., such monomers having the following generalstructural formula:

    A--CF.sub.2 --O--(CF.sub.2 --CF.sub.2 --O).sub.m --(CF.sub.2 --O).sub.n --CF.sub.2 --Z

wherein, m is an integer from 2 to 20, n is an integer from 2 to 30, Ais selected from CF₃ --, CH₃ --, CH₂ F--, and CF₂ H--, and Z has theformula which includes one of the following: ##STR18## or mixturesthereof.

The principal sulfone monomers embodied in the present invention whichcontribute to the increased oxygen permeability and strength of thecopolymer for contact lenses are represented by the following generalstructural formula: ##STR19## wherein, A is selected from one of thefollowing: ##STR20## wherein, B is C₁ to C₂₀, alkyl, cyclic or phenylgroups and n is an integer from 1 to 5.

The preferable sulfone monomers which are useful in the presentinvention are:

methyl vinyl sulfone,

methyl styrene sulfone,

ethyl vinyl sulfone,

ethyl styrene sulfone,

propyl vinyl sulfone,

propyl styrene sulfone,

phenyl vinyl sulfone,

phenyl styrene sulfone,

cyclohexyl vinyl sulfone,

cyclohexyl styrene sulfone,

pentyl vinyl sulfone,

pentyl styrene sulfone,

butyl vinyl sulfone,

butyl styrene sulfone,

phenoxyethyl vinyl sulfone,

phenoxyethyl styrene sulfone,

divinyl sulfone,

methacryloxyethyl methyl sulfone,

methacryloxyethyl ethyl sulfone,

methacryloxyethyl propyl sulfone,

methacryloxyethyl butyl sulfone,

methacryloxyethyl phenyl sulfone,

methacryloxyethyl pentyl sulfone,

methacryloxyethyl styrene sulfone, and

mixtures thereof.

The copolymer plastic material of the present invention alsoincorporates hardening agents such as methyl methacrylate, ethylmethacrylate, propyl methacrylate, cyclohexyl methacrylate, glycidylmethacrylate, phenoxyethyl methacrylate, phenyl methacrylate,tetrahydrofurfuryl methacrylate, methyl acrylate, ethyl acrylate, propylacrylate, cyclohexyl acrylate, phenoxyethyl acrylate, phenyl acrylate,tetrahydrofurfuryl acrylate, dimethyl itaconate, diethyl itaconate,dipropyl itaconate, dicyclohexyl itaconate, diphenyl itaconate, vinylbenzene (styrene), divinyl benzene and equivalents.

The contact lens material is further modified by the incorporation ofwettability and cross-linking agents to improve overall performance ofthe contact lens on the human eye. Such representative monomers ofwettability agents are acrylic acid, methacrylic acid, 2-hydroxyethylacrylate, 2-hydroxyethyl methacrylate, 2,3-dihydroxypropyl acrylate,2,3-dihydroxypropyl methacrylate, and/or N-vinyl 2-pyrrolidinone ormixtures thereof.

Representative cross-linking agents are ethyleneglycol dimethacrylate,diethyleneglycol dimethacrylate, triethyleneglycol dimethacrylate,tetraethyleneglycol dimethacrylate, dimethacrylate siloxanyl estermonomer (PSX-563A), ethyleneglycol diacrylate, diethyleneglycoldiacrylate, triethyleneglycol diacrylate, tetraethyleneglycoldiacrylate, divinyl benzene, divinyl sulfone and/or trimethylolpropanetrimethacrylate or mixtures thereof.

A variety of other ingredients may be included in the polymerizationmixture so that to either enhance or provide specific properties. Forexample, wettability of the surface of the lens is a very importantcharacteristic for contact lenses to possess in order to provide comfortand good visual acuity. In addition to already disclosed wettabilityagents named herein, additional ethylenically unsaturated monomers canalso be incorporated that have a hydrophilic group such as hydroxy,carboxy, carbonamido sulfonyl, and sulfonamido groups. As an example, itcan be 2-carboxyethyl acrylate, 2-carbonamidoethyl methacrylate,2-sulfoethyl methacrylate, 2-sulfonamidoethyl acrylate, vinyl sulfonicacid, and mixtures thereof.

The preferred composition of the present invention comprises of:

(a) from about 5 to 65 weight percent of ethylenically unsaturatedorganosiloxanylalkoxy ester monomer of acrylic and/or methacrylic acidsand siloxanylalkyl ester monomers of itaconic acid or mixtures thereof;

(b) from about 2 to 30 weight percent of ethylenically unsaturatedperfluoralkyl ester monomer or mixtures thereof;

(c) from about 1 to 25 weight percent of ethylenically unsaturatedsulfone monomer or mixtures thereof;

(d) from about 10 to 70 weight percent of hardening agent monomer(preferably, methyl methacrylate, cyclohexyl methacrylate and/ordimethyl itaconate) or mixtures thereof;

(e) from about 1 to 18 weight percent of difunctional cross-linkingmonomer (preferably triethyleneglycol dimethacrylate,tetraethyleneglycol dimethacrylate) or mixtures thereof; and

(f) from about 1 to 15 weight percent of wetting agent monomer(preferably methacrylic acid or N-vinyl 2-pyrrolidinone) or mixturesthereof.

The copolymer plastic can also be prepared without perfluoralkyl estermonomer and/or sulfone monomer and the material would still possess highoxygen permeability and good wettability.

The polymerization of the oxygen permeable material for the manufactureof contact lenses disclosed in the present invention is accomplished byusing free-radical polymerization, such techniques are disclosed in theprior art.

EXAMPLE 1

This example illustrates the preparation oftris(trimethylsiloxy)methacryloxyethoxysilane, an organosilicone monomeruseful in the present invention. To a three-necked, round bottom, 12liter flask equipped with mechanical stirrer and cooling system is added5 liters of dry toulene, 2 moles of 2-hydroxyethylmethacrylate and 2moles plus 10% excess of triethylamine. The flask content is cooled downto about 5° C. When the temperature is reached, start addition of 2equivalent moles of tris(trimethylsiloxy)chlorosilane; all additiontakes about one hour. Then the temperature is raised to 30° C. and thestirring is continued for 6 hours. After the reaction is completed, thewhite precipitation of triethylamine hydrochloride is filtered off;distillation of toulene proceeds at about 45° C. under aspirator vacuum.The crude product is washed twice with cold water and then 2 times with5% bicarbonate solution; then the crude product is washed again 2 timeswith cold water. The crude product is dried over anhydrous MgSO₄ for 3hours; the MgSO₄ is removed by filtration and the product is strippedunder high vacuum at 75° C. The refractive index n_(D) ²⁵ is1.4112±0.001; the infrared spectrum confirmed the structure. The sameprocedure is used for the preparation oftris(pentamethyldisiloxanyl)methacryloxyethoxysilane,bis(pentamethyldisiloxanyl)trimethylsiloxanylmethacryloxyethoxysilane,and bis(trimethylsiloxy)pentamethyldisiloxanylmethacryloxyethoxysilaneif the starting material tris(trimethylsiloxy)chlorosilane is replacedwith pentamethylchlorosilane and trimethylchlorosilane in the desiredmolar ratio.

EXAMPLE 2

This example illustrates the preparation of the representativeperfluoroalkyl ester monomer useful in the present invention. A 12liter, 3-necked, round bottom flask equiped with a mechanical stirrerand cooling system is charged with 5 liters of toulene, 3 moles of1,1',2,2'-tetrahydroperfluorohexanol and 3 moles plus 10% excess oftriethylamine. The flask content while stirring is cooled down to about5°-10° C. until the temperature is reached, then start addition of 1mole of trichloromethacryloxypropylsilane; all addition takes about onehour. When all addition is completed the temperature of the reactionmixture is raised to 30° C. and stirring is continued for 10 hours.After the reaction is completed, white precipitation of triethylaminehydrochloride is filtered off; distillation of toulene proceeds at about45° C. under aspirator vacuum. The crude product is washed twice withcold water, then 2 times with 5% sodium bicarbonate solution and thenthe crude product is washed again 2 times with cold water. The crudeproduct is dried over anhydrous MgSO₄ for 3 hours; the MgSO₄ is removedby filtration and the product is stripped under high vacuum at 75° C.The monomer is then ready to be used in the polymerization process.

EXAMPLE 3

This example is an illustration of the preparation of2,3-di[tris(trimethylsiloxy)siloxanyl]methacryloxypropane. The 12 literflask equipment with a mechanical stirrer, additional funnel and coolingsystem is charged with 5 liters of toulene, 2 moles of2,3-dihydroxypropylmethacrylate and 2 moles plus 10% excess oftriethylamine. The contents of the flask is cooled down to 5° C., thenaddition of 2 moles of tris(trimethylsiloxy)chlorosilane proceeds inabout a period of one hour. When all addition is completed thetemperature of the reaction mixture is elevated to 30° C. and stirringis continued for about 8 hours. After the reaction is completed, whiteprecipitation of triethylamine hydrochloride is filtered off;distillation of toulene proceeds at about 45° C. under aspirator vacuum.The crude product is washed twice with cold water and 2 times with 5%sodium bicarbonate solution and then the crude product is washed again 2times with cold water. The crude product is dried over anhydrous MgSO₄for 3 hours; the MgSO.sub. 4 is removed by filtration and the product isstripped under high vacuum at 75° C. The refractive index of the productis 1.4083±0.002. The same procedure is used for the preparation of2,3-di(pentamethyldisiloxanyl)methacryloxypropane if the startingmaterial tris(trimethylsiloxy)chlorosilane is replaced withpentamethylchlorodisiloxane.

EXAMPLE 4

This example illustrates the preparation of representative copolymermaterial for contact lenses. To a 200 ml flask is added 35 grams oforganosilicone monomer previously prepared in Example 1,tris(trimethylsiloxy)methacryloxyethoxysilane, 15 grams of2,3-di[tris(trimethylsiloxy)siloxanyl]methacryloxypropane, 2 grams ofmethacrylate dimer (PSX-563A), 10 grams of cyclohexyl methacrylate, 5grams of methacrylic acid, 2.5 grams of N-vinyl 2-pyrrolidinone, 5 gramsof perfluoro monomer prepared in Example 2, 10 grams oftriethyleneglycol dimethacrylate, 14 grams of methyl methacrylate, 5drops of D&C #6 color dye, 0.5 ml of t-butyl peroxypivalate and 0.2grams of benzoyl peroxide. All contents are mixed thoroughly and pouredinto polypropylene tubes, molds or sililated glass tubes, closed andpolymerized in water bath at 40° C. for a period of about 18 hours. Therods are then put into a thermostated oven for at least 24 hours, havinga temperature of about 100° C. The copolymer plastic is transparent,hard and suitable for the machining of highly permeable contact lenses.

EXAMPLE 5

This example illustrates the preparation of representative copolymerplastic material for contact lenses made only from siloxanyl monomer asa source of oxygen permeability. To the 200 ml flask is added 41 gramsof 2,3,-di[tris(trimethylsiloxy)siloxanyl]methacryloxypropane, 10 gramsof cyclohexyl methacrylate, 4.5 grams of methacrylic acid, 5 grams ofdiethyleneglycol dimethacrylate, 39 grams of methyl methacrylate, 0.4grams of t-butyl peroxyoctoate and 0.1 grams of benzoyl peroxide, allcomponents are mixed thoroughly and poured into polypropylene tubes,molds or sililated glass tubes closed with stoppers and polymerized in awater bath or thermostated oven set at 45° C. for a period of about 20hours. The rods or blanks are then put into a thermostated ovenpreheated at 105° C. for a period of 24 hours. The copolymer plastic istransparent, hard, oxygen permeable, wettable and suitable formanufacturing oxygen permeable contact lenses.

EXAMPLE 6-13

This example illustrates the preparation of optically clear plasticprepared in accordance with the polymerization procedure described inExample 5, except the amounts and kinds of monomers may be different asshown in the following table:

                  TABLE                                                           ______________________________________                                                       Example Number                                                 Components (Parts)                                                                             6     7     8   9   10  11  12  13                           ______________________________________                                        2,3-di [tris(trimethylsiloxy)-                                                                 35    30    20  10  0   15  20  20                           siloxanyl]methacryloxypropane                                                 tris(trimethylsiloxy)-                                                                         0     10    20  30  40  0   15  15                           methacryloxyethoxysilane                                                      tris(dimethylhydrosiloxy)-                                                                     5     0     5   0   10  15  5   10                           methacryloxypropylsilane                                                      methacryloxymethylpenta-                                                                       0     5     0   0   0   15  5   0                            methyldisiloxane                                                              cyclohexyl methacrylate                                                                        12    10    5   0   10  6   10  0                            dimethyl itaconate                                                                             10    5     20  20  0   10  0   30                           triethyleneglycol                                                                              6     8     7   5   4   10  6   8                            dimethacrylate                                                                methyl methacrylate                                                                            25    28    30  30  25  30  40  0                            methacrylic acid 5     45    0   5   4   6   0   4                            N--vinyl 2-pyrrolidinone                                                                       3     0     6   0   3   0   5   2                            vinyl benzene    0     5     0   3   4   10  0   10                           ______________________________________                                    

EXAMPLE 14

This example illustrates the preparation of oxygen permeable copolymerplastic for contact lenses made from siloxanylalkoxy ester monomer andperfluoroalkyl ester monomer as a source of oxygen permeability. To a200 ml flask is added 35 parts ofbis(pentamethyldisiloxanyl)trimethylsiloxymethacryloxyethoxysilane, 15parts of cyclohexyl methacrylate, 10 parts oftris(1,1'-dihydroperfluorohexyloxy)methacryloxypropylsilane, 3 parts ofN-vinyl 2-pyrrolidinone, 7 parts of tetraethyleneglycol dimethacrylate,5 parts of methacrylic acid, 25 parts of methyl methacrylate, 0.5 partsof t-butyl peroxypivalate and 0.2 parts of benzoyl peroxide; thepolymerization is carried out by the same procedure as described inExample 5. The resulting plastic is transparent, hard, stable, wettableand suitable for machining of highly permeable contact lenses.

EXAMPLE 15-22

Samples of optically clear plastic are prepared in accordance with thepolymerization procedure described in Example 14, except the amounts andkinds of components may be different, as shown in the following table:

                  TABLE                                                           ______________________________________                                                       Example Number                                                 Components (Parts)                                                                             15    16    17  18  19  20  21  22                           ______________________________________                                        tris(1,1'-dihydroperfluoro-                                                                    10    0     5   20  40  20  20  15                           hexyloxy)methacryloxypropyl-                                                  silane                                                                        bis(1,1',2,2'tetrahydro-                                                                       0     15    5   0   0   5   3   5                            perfluorobutyl)itaconate                                                      2,3-di [tris(trimethylsiloxy)-                                                                 30    25    10  20  20  5   0   10                           siloxyanyl]methacryloxypropane                                                tris(trimethylsiloxy)meth-                                                                     10    15    25  5   0   30  40  20                           acryloxyethoxysilane                                                          di(pentamethyldisiloxanyl-                                                                     5     0     5   10  5   5   5   8                            ethyl)itaconate                                                               dimethyl itaconate                                                                             10    0     6   10  30  15  0   12                           methyl methacrylate                                                                            20    30    18  10  10  20  18  20                           cyclohexyl methacrylate                                                                        10    15    8   20  0   0   15  0                            methacrylic acid 3     4     5   1   3   5   3   6                            N--vinyl 2-pyrrolidinone                                                                       0     3     2   6   2   0   4   0                            vinyl benzene    0     2     6   0   3   8   0   0                            diethyleneglycol 6     0     2   4   6   0   0   1                            dimethacrylate   6     0     2   4   6   0   0   1                            triethyleneglycol                                                                              0     6     3   4   0   6   10  6                            dimethacrylate                                                                ______________________________________                                         *All samples of the above copolymer plastic are clear, transparent and ga     permeable.                                                               

EXAMPLE 23

This example illustrates the preparation of oxygen permeable copolymerplastic for contact lenses from siloxanylalkoxy ester of methacrylicacid and sulfone monomer as a source of oxygen permeability; consistingof 40 parts of tris(trimethylsiloxy)methacryloxyethoxysilane, 10 partsof cyclohexyl methacrylate, 8 parts of methyl vinyl sulfone, 20 parts oftetrahydrofurfuryl methacrylate, 5 parts of 2-hydroxyethyl methacrylate,7 parts of N-vinyl 2-pyrrolidinone, 7 parts of methyl methacrylate and0.4 parts of t-butyl peroxypivalate are polymerized. The resultingcopolymer plastic has a hardness of 86±2 as measured on the Shore D(ASTM-2240) hardness tester.

EXAMPLE 24

A contact lens has been manufactured from the oxygen permeable materialof the present invention using standard, conventional manufacturingtechniques known in the art. The base curve of the lens was cut at 7.80mm, the front curve of the lens was cut at 8.21 mm, the center thicknessof the lens was 0.19 mm. The contact lens was then polished using atechnique widely known in the contact lens industry. The base curve ofthe lens was 7.81 mm; after the lens was polished the base curveremained at 7.81 mm. The lens was soaked over 72 hours in Soaclenssolution and the base curve remained at 7.81 mm.

EXAMPLE 25-32

Samples of optically clear plastic are prepared in accordance with thepolymerization procedure described in Example 4, except the amounts andkinds of components may be different as shown in the following table:

    ______________________________________                                                       Example Number                                                 Components (Parts)                                                                             25    26    27  28  29  30  31  32                           ______________________________________                                        tris(trimethylsiloxy)                                                                          25    40    30  40  30  45  10  0                            methacryloxyethoxysilane                                                      tris(trimethylsiloxy)-                                                                         10    0     10  5   10  0   20  30                           methacryloxypropylsilane                                                      1,1',2,2'-tetrahydroper-                                                                       10    5     0   10  2   0   5   0                            fluorohexyl methacrylate                                                      tris(1,1'-dihydroperfluoro-                                                                    5     0     5   0   2   10  0   20                           butyloxy)methacryloxy-                                                        propylsilane                                                                  methyl vinyl sulfone                                                                           0     5     6   0   10  0   10  10                           methyl methacrylate                                                                            30    30    29  30  21  35  30  15                           cyclohexyl methacrylate                                                                        10    10    11  10  10  0   10  15                           methacrylic acid 5     5     4   2   5   5   5   4                            diethleneglycol  5     5     5   3   10  5   10  6                            dimethacrylate                                                                ______________________________________                                         *All samples of the above copolymer plastic are hard, transparent and         easily machinable.                                                       

EXAMPLE 33

The polymerization of a mixture of 20 parts of2,3-di[tris(trimethylsiloxy)siloxanyl]methacryloxypropane, 20 parts oftris(trimethylsiloxy)methacryloxypropylsilane, 10 parts ofbis(1,1',5-trihydroperfluoropentyl)itaconate, 10 parts of cyclohexylmethacrylate, 8 parts of ethyleneglycol dimethacrylate, 4 parts ofmethacrylic acid, 3 parts of N-vinyl 2-pyrrolidinone and 25 parts ofmethyl methacrylate are polymerized by using a free-radical catalysts,as shown in Example 5, in polypropylene base curve premolded caps. Theresulting plastic gives a transparent, concave plug.

EXAMPLE 34

The polymerization procedure of Example 5 is repeated, except theamounts and kinds of components in the polymerization are changed asfollows: 45 parts oftris(trimethylsiloxy)siloxanylmethacryloxyethoxysilane, 10 parts oftris(1,1',2,2'-tetrahydroperfluoropentyloxy)methacryloxypropylsilane, 10parts of cyclohexyl methacrylate, 9 parts of triethyleneglycoldimethacrylate, 5 parts of methacrylic acid, 3 parts of N-vinyl2-pyrrolidinone and 18 parts of methyl methacrylate are polymerized byusing free-radical initiator at 47° C. The plastic is then removed fromthe molds, transferred into a thermostated oven which is set at 108° C.and the copolymer plastic is cured for an additional 24 hours. Theresulting plastic has an oxygen permeability of about 91×10⁻¹¹ (cm²/sec)(ml O₂ /ml×mm Hg) at 35° C., as analyzed on the Schema-VersataeModel #920 instrument (an analytical technique widely used in theindustry).

The embodiments of the invention which are claimed as an exclusiveproperty or priviledge are defined as follows:
 1. An oxygen permeablecontact lens consisting essentially of an organic polymer selected fromthe group consisting of organosiloxanylalkoxy ester monomer of acrylicand methacrylic acid which has the structural formula: ##STR21## whereinA is C₁ to C₆ alkyl, cycloalkyl or phenyl, X and Y are C₁ to C₆, alkyl,cyclic or phenyl groups and/or groups of the following structure:##STR22## m being an integer from 1 to 5 and R is methyl group orhydrogen; and an organosiloxanylalkoxy ester monomer of acrylic ormethacrylic acid having the following structural formula: ##STR23## nbeing an integer from 1 to 3, wherein X and Y are C₁ to C₆, alkyl,cyclic or phenyl groups or groups of the following structure: ##STR24##m being an integer from 1 to 5 and R is methyl group or hydrogen,wherein the contact lens has an oxygen permeability of about 91×10⁻¹¹(cm² /sec) (ml O₂ /ml×mmHg) at 35° C.
 2. An oxygen permeable contactlens consisting essentially of from about 5 to 70 weight percent of amonomer selected from the group consisting of organosiloxanylalkoxyester monomer of acrylic and methacrylic acids having the followingformula: ##STR25## wherein A is C₁ to C₆ alkyl, cycloalkyl or phenyl; Xand Y are C₁ to C₆, alkyl, cyclic or phenyl groups or groups of thefollowing structure: ##STR26## m being an integer from 1 to 5 and R ismethyl group or hydrogen; and an organosiloxanylalkoxy ester monomer ofacrylic or methacrylic acid having the following structural formula:##STR27## n being an integer from 1 to 3, wherein X and Y are C₁ to C₆,alkyl, cyclic or phenyl groups or groups of the following structure:##STR28## m being an integer from 1 to 5 and R is methyl group orhydrogen; said organosiloxanylalkoxy ester monomers of acrylic ormethacrylic acid being partially substituted with organosiloxanylalkylester monomers having the following structural formula: ##STR29##wherein X and Y are C₁ to C₆, alkyl, cyclic or phenyl groups or groupsof the following structure: ##STR30## m being an integer from 1 to 6, nbeing an integer from 1 to 3 and R is methyl group or hydrogen; or theformula: ##STR31## wherein X and Y are C₁ to C₆, alkyl, cyclic or phenylgroups or groups of the following structure: ##STR32## m being aninteger from 1 to 6, n being an integer from 1 to 3, A is selected formC₁ to C₆, alkyl or phenyl groups, R is methyl group or hydrogen and D ishydrogen or hydroxy group; or the formula: ##STR33## wherein X and Y aregroups of the following structure: ##STR34## m being an integer from 1to 5, n is an integer from 1 to 3, wherein A is selected from C₁ to C₆,alkyl, cyclic or phenyl groups and R is methyl group or hydrogen; or thefollowing formula: ##STR35## wherein X and Y are C₁ to C₆, alkyl, cyclicor phenyl groups or groups of the following structure: ##STR36## m beingan integer from 1 to 5, n being an integer from 1 to 3, wherein A isselected from the group consisting of C₁ to C₆, alkyl, cyclic and phenylgroups and B is methyl group, hydrogen or hydroxy group, wherein thecontact lens has an oxygen permeability of about 91×10⁻¹¹ (cm² /sec)(ml/O₂ /ml X mmHg) at 35° C.